Cushioning means for clutches



Aug. 20, 1935.

F. E. MUNSCHAUER CUSHIONING MEANS FOR CLUTCHES Filed April 8, 1955 3 Sheets-Sheet 1 BY 7% m ATTORN EYS Allg- 1935. F, E. MUNSCHAUER CUSHIONING MEANS FOR CLUTCHES Filed April 8, 1953 3 Sheets-Sheet 2 INVENTOR BY W ATTORN EYS 1935. F. E. MUNSCHAUER 2,011,822

CUSHIONING MEANS FOR CLUTCHES Filed April 8, 1935 3 Sheets-Sheet 3 ATTORN EYS Patented Aug. 2c, 1935 2,011,822

* UNITED STATES, PATENT OFFICE CUSHIONING MEANS FOR CLUTCHES Frederick E. Mnnschaucr, Buffalo, N. 1., as-

signor to Niagara Machine 8; TooLWorks, Buffalo, N. Y., a corporation of New York Application April 8, 1933, Serial No. 665,150 11 Claims. (01. 192-24) Thisinvention relates to a cushioning means ple in construction and composed of few parts for clutches which are adapted tocouple and and can be manufacturedand assembled at low uncouple two relatively movable members and cost. is more particularlyintended to be employed In the accompanying drawings:

in clutches for coupling the drive shaft of a Fig. 1 is afragmentary vertical longitudinal 5 high speed metal forming machine with a source section of the clutch mechanism for a metal of power although the invention can be advanforming machine embodying one form of my tageously incorporated in the clutches of high invention. speed machines for other purposes; With the Fig. 2 is a side elevation of the clutch sleeve present demand for metal forming machines opand inner cushion member or ring of the clutch 10 erating at higher and higher speeds, the clutches mechanism which cooperates with the clutch which have heretofore been designed for metal sleeve and with the other parts of the cushionforming machines have proved inadequate. Not ing device.

only are the former types of clutches extremely Figs. 3 and 4 are vertical cross sections taken 5 noisy when the speed at which the machine is on the correspondingly numbered lines of Fig. l. operated is increased but the strain imposed Fig. 5 is a vertical section of'the outer cushupon the clutch and upon the other parts of the -ion member or rim of the clutch mechanism -machine in stopping and starting its operation shown in Figs. 1 and 3.

is so great as to cause excessive wear and fre- Fig. 61s a vertical longitudinal section, similar quent replacements, thereby overcoming the adto Fig. 1, but showing a modified form of my in- 20 vantage obtained by driving the metal forming vention.

machine at an increased speed. Fig. 7 is a vertical transverse section, taken It is therefore the principal object of the online 1-1, Fig,6 present invention to, P o Cushioning means In the following description similar characters in the-clutch. Structure which cyshioning means of reference indicate like parts in the several 5 are interposed between the driving clutch memfigure of the drawings. v be! the main 0: the metal -forming th u t-Honing mean of the presfint maqhme and therekfy absforb and reheve the invention is applicable to clutch mechanisms of strain on the clutch in rapidly coupling and unvarious kinds of machines it is particularly Coupling the main Shaft of the machine with tended for use in connection with high speed 30 a power source. The cushioning means are also the lutch so designed as to materially reduce the noise of zgz f gfi g zzm g g 1 232? servicg and clutch m engagmg {and dlsengagmg and to by way of illustration of one of its uses is shown Insure a smooth and rename engz-a'gement of the as driving the horizontal main or drive shaft clutch jaws each time the clutchis operated. m or met 1 for machine such as a punch 35 Another object of the present invention is to h mmg r the like this main or provide such a cushioning means which absorbs 2 g g z 3 0 maled in Suitable heap the force of back lash strains upon the clutch 5 a g f th f rmi machine and prevents the clutch from being accidentally g gafi z ag; asomterepoged a thi I 40 thrown out because of such back lash strains. A main. or drive shaft m and a driving pulley I3 40 Another aim is to provide such a cushioning means for a high speed clutch which will stand is adapted to be rotated either by bellt up under heavy loads and is ruggedly constructed (not shown) otherwise from m f 9 so as not to require repair, adjustment or re- Source of p e ub l4 0! h dr v placements even under conditions of constant n evis' 0n the reduced Outef end and steady service. of the main or drive, shaft l0 and this hub is Another purpose is to provide such a cushionshown as being rotatably secured on the end l5 ing means for a clutchin which positive limit of the drive shaft by a retaining plate H which stop are provided to limit the action of the holds the hub l4 against the shoulder iii of cushioning means and insure a positive drive the drive shaft. It will be understood, however, 50

through the clutch as well as avoiding undue that the particular manner oi mounting the puls rain upon the cushioning means and undue reley I 3 on the reduced end l5 of the main drive bound action of the cushioning-means. shaft is by way of example only and that ball O her objects are to provide such a cushionor roller bearings could be substituted for the ing means for high speed clutches which is simbearings shown, in which case a different form 55 of retaining means between the pulley and the drive shaft would necessarily be required.

When the machine is idle the pulley I3 is uncoupled from the drive shaft l and its hub turns 'freely on the reduced part l5 of the shaft so that the working parts of the machine remain at rest, but upon coupling the shaft with the driving pulley power is transmitted to the working parts of the machine to complete a forming operation.

The clutch mechanism which is shown in Figs. 1-5 represents one form of my invention, and as there shown the same is constructed as follows:

The numeral It! represents a clutch sleeve which is mounted on and compelled to turn with the main drive shaft l0 but is free to slide thereon by means of a plurality of longitudinal splines l9 annularly disposed on the shaft l0 and engaging with corresponding longitudinal splines 20 in the bore of the clutch sleeve l8. Any suitable means may be provided for moving this clutch sleeve into and out of its operative position and in the present case the organization is such that.

when the sleeve is moved outwardly or forwardly the clutch operates to couple the pulley with the drive shaft and when the clutch sleeve is moved inwardly or rearwardly the clutch mechanism operates to disconnect the pulley from the drive shaft. The pulley is continuously rotating and consequently the engagement or disengagement of the clutch causes the shaft to be revolved accordingly. a

Any suitable means can be employed for moving the clutch sleeve outwardly or forwardly into its operative position, and as illustrated, these means consist of a projecting helical compressionspring 2| disposed at the rear or outer end of the clutch sleeve l8 and a bearing disk 22 interposed between the rear end of the spring and the adjacent bearing II on the main frame in which the main or drive shaft i0 is journaled. For coupling the clutch this spring 2| moves the clutch sleeve outwardly and cooperates with other parts for connecting the driving pulley with the main or drive shaft and when it is desired to uncouple the pulley.

and shaft, the clutch sleeve is moved rearwardly or inwardly into its inoperative position, shown in i Instead of effecting a positive, unyielding connection between the clutch sleeve l8 and the pulley l3, as is commonly the case; this connection is effected by means which provide a cushioning or shock absorbing action which absorbs the shock of coupling the stationary 'v e shaft with r the rotating pulley and thereby eases the strain of the hub M of the driving pulley and the front or outer-side of the clutch sleeve l8. The bore of this ring is preferably spaced from the shaft l0 and is preferably held concentric with the axis of the drive shaft II) by providing the front side of this inner cushion ring with an annular neck 24 which sets in an annular recess 25 formed on shaft.

the rear side of the pulley hub l4. On its rear side this inner cushion ring 23 is provided with an annular row of clutch or coupling jaws 26 and on 'ts periphery this-inner cushion ring 23 is provided with an annular row of cushion or relief teeth 21. On the corresponding front or outer end the clutch sleeve I8 is provided with an annular row of clutch jaws 28 which are adapted to be moved into and out of engagement with the clutch jaws of the inner cushion ring 23 for the coupling and uncoupling of the pulley and drive The cooperating or driving faces of the clutch jaws 26 and 28 of the inner cushion ring 23 and the clutch sleeve l8 are parallel with the axis of the drive shaft and are disposed at a constant angleto the radii of the shaft generated through, say, the center of each jaw. In other words, the planes of the driving faces of the jaws are tangential to a circle, indicated at A, generated within the 'jaws and concentric with the shaft. In the same manner the trailing faces of the jaws, while not disposed in their entirety parallel to the axis of the drive shaft, are also arranged tangential to the same assumed circle A or are disposed at the same angle relative to the radius of the shaft. This form of jaws, as compared with radially disposed teeth, not only provides jaws having more metal in the direction of the strain against them but also provides a wedging action of the two sets or rows of jaws which has the effect of compressing the metal of the teeth to such an extent that a cushioning or resilient effect is produced. This wedging action is due, byactual test, to the yield of the jaws when subjected to thesudden and heavy load and backlash strains. Without such yield of the jaws, no wedging action could, of course, occur and the yield of the teeth is increased by their mutual wedge action. Many clutches embodying this feature of the invention have been in continuous service and the cushioning action of the inclined jaws is remarkably effective in relieving load and backlash. strains. The wedging action of the teeth, through their actually yielding, also provides a frictional resistance to the relative rotation of the driving and driven members coupled by the clutch, thereby providing a frictional cushioning means between these elements and absorbing a part of the strain of impact when a load is imposed on the clutch in coupling it. It will be-appreciated that the jaws of every positive clutch must yield in order to provide the time necessary to transmit the force from a rapidly rotating pulley or flywheel to a stationary load. Without this yield and time element in the application of the power to the load, the strain would be infinite and the clutch immediately break. The present invention is designed to take the greatest advantage of this inherent yield and increase its effect so asto be effective as a cushioning means inherent to the clutch.

The form of the jaws 26 and 28 is such that they will freely engage when the sleeve I8 is moved toward the ring 23 which, of course, rotates with the pulley, and at the same time will positively transmit both driving and backlash strains when engaged. In order to permit the jaws to freely engage, clearance between the jaws is-provided by rounding ,the outer part of the trailing face of each jaw so that these faces merge with the end faces of the jaws. The driving faces of the jaws, are, however, parallel with a the axis of the clutch so as to provide a positive drive and the inner part of the trailing face of each jaw is also parallel with this axis or less than v the angle of repose so that when these faces en gage (under backlash strains on the clutch),

web 32 connecting the peripheral and bore parts.

The relatively wide, outer or peripheral part 29 of this outer cushion ring is secured to the hub 4 of the driving pulley and to hold this in centered relation to the drive shaft and other parts of the clutch is preferably set within a recess 30 in the rear side of the hub l4. This ring is rigidly 1 connected, through its relatively wide peripheral portion with the hub of the pulley by a plurality of connecting bolts, each of which passes with its shank 33 through the pulley hub and is provided at its rear end with a conical head 34 which engages with a correspondingly shaped opening 35 in the adjacent part of the relatively wide outer rim 29 of this cushion ring and holds this outer rim against the rear face of the hub. The bolts are provided with the usual nuts 36 at their front ends which bear against lock washers 31 and draw the outer cushion ring firmly against the hub of the pulley.- In its bore, the outer cushion ring is provided with an annular row of relief teeth 38 which are in permanent mesh with the relief teeth 21 on the inner cushion ring, as shown in Figs. 1 and 3. 'i'These teeth 2'! and 38 are preferably of helical form so that upon coupling the sleeve clutch the cooperating inclined faces will produce a Wedging action which will drive the inner part 3| of the outer cushion ring axially and flex the intermediate web 32 of this ring. This axial movement of the'inner part 3| of the outer coupling ring is, of course,'resisted by the resilient web 32 and is also resisted by the friction of the teeth and thereby provides an additional yielding or cushion effect be'tween the driven and driving elements of the clutch. In addition, of course, there is a resilient-compress'ion of the metal of the teeth 21 and 38 which provides a further cushioning effect. The axial movement of the inner rim 3| of the outer cushion ring is limited so that under both driving and rebound strains the outer cushion ring can be flexed to a predetermined degree only and thereafter a positive or unyielding drive obtained through this outer cushion ring. For this purpose the. inner rim 3| of the outer cushion ring, when at rest, is spaced to provide a predetermined gap 42 which limits the axial outward movement of the inner rim 3| or toward the hub I 4 of the driving pulley. The movement of the inner rim 3| of the outer cushion ring in the opposite direction is limited by the provision of a predetermined gap 43 between the corresponding side of the inner part 3| of the outer cushion ring and a retaining'ring or member v39 which is secured to the relatively wide outer rim 29 of'this outer cushion by a plurality of bolts 40. The shank of each of these bolts is tightly fitted in the hub' M of the driving pulley and the retaining ring 39 but passes through a slightly enlarged opening 4| in the outer rim portion 29 of the outer cushion ring, as shown in Fig. l. The retaining ring 39 is also preferably provided with a rearwardly projecting inner or annular flange 44, which flange encloses the jaws of the clutch sleeve l8 and the inner retaining ring 39.

action occurs under both driving and rebound r 3 cushion ring 23. It has been found that this flange 44 greatly reduces the noise of engagement of the jaws and, when packed with grease, practically eliminates all noise in the clutch.

The helical inclination of the driving faces of the relief teeth 21, 38 is preferably such that when a wedging action is produced by these several teeth, upon coupling the pulley with the drive shaft while the latter is at rest, this wedging action will operate to deflect and press the inner or bore portion 3| of the outer cushion ring against the corresponding face of the retaining ring 39. thereby closing the gap 43 and obtaining a positive drive through the clutch. The helical inclination of the non-driving faces of these'teeth is also preferably such that under excessive rebound strains the inner rim 3| of the outer cushion ring will be driven against the hub .l4 and thereby close the gap 42. When at rest the inner rim 3| of the outer cushion ring assumes its central positfon with the gaps 42 and 43 at its opposite sides. I

This flexing of the inner rim 3| of the cushion ring is only possible, of course, because the pressure transmitting faces on both the driving and trailing sides of each jaw 26 and -28 are parallel with the axis of the clutch, or nearly so, and

thereby positively transmit both load and backto the drive shaft i0 when the clutch is coupled,

which blow is taken up partly by the frictional resistance of the cooperating inclined faces of the relief teeth 21 and 38 on the inner and outer cushion rings; also by the frictional resistance of the cooperating inclined surfaces of the clutch jaws 26, 28; also by the yielding of the metal of these teeth and jaws; also by the internal flexibility of the outer cushion ring; also by the internal flexibility of the retaining ring 39 and also by the yielding of the bolts 48 which secure the This flexibility or yielding strains and is particularly -effective in avoiding the delivery of a dead blow and undue strain through the clutch when the clutch is suddenly coupled to start the machine and also avoids unnecessary wearand noise which has accompanied the coupling action of clutches on machines of a retaining flange 39| formed integrally with and projecting inwardly-from the outer cushion ring 29L This retaining flange 33| is preferably formed to enclose the jaw teeth of the clutch to avoid noise in coupling the clutch. The'inner cushion ring 23| is provided on its rear side with an annular row of clutch jaws 26| which are formed in the same manner as the clutch jaws 26 in the form of the invention shown in Figs. 1-5 and are adapted to be engaged by a similar row of clutch jaws 2! on the front end of the clutch sleeve IN. The inner cushion ring BI is free to move axially to a limited extent relative to the driving pulley and drive shaft l0 and is preferably held in its rearmost position against the front side of the flange 39I by spring means which preferably consist of a plurality of helical compression springs 32!, each of which is seated in a socket 3 on the rear side of the driving pulley hub and engages with the front side of the inner cushion ring 23 l as shown in Fig. 6.

The cooperating relief teeth Zll and 38l and the clutch jaws 26l and 28L by reason .ofthein 32! which function until the inner cushion ring' BI is driven against the adjacent face of the hub of the pulley. The opposite or rearward movement of the inner cushion ring 23! is yieldingly resisted by the flange 39| of the outer cushion ring-291, this flange I having inherent flexii y.

By arranging the helical teeth of the inner and outer cushion rings 23! and 29! so that the inner cushion ring 22 is driven rearwardly or against the flange 391 under coupling strains the springs 32! can be eliminated and suflicient'dampening action of the blow obtained by the yield of the metal of the jaws HI and I and the frictional sliding of these jaws to one another; the yield of v the metal of the helical teeth 21 and 38| relative to one another and their frictional movement relative to one another; and the yield of the inner cushion ring 23l backwards.

The relief teeth can be generated or cut with a broad pressure angle, say 45 or even more, thus producing a wedging action of the teeth themselves independent of any helical angle. Experimental parts of 45 pressure angle and 45 helical angle are now being formed. These teeth, of course, can be involute or merely inclined planes or of other contours.

Both of the forms of cushioning devices herein shown and described are comparatively simple in construction, low in cost of manufacture, are unlikely to get out of order and are capable of being installed where a small amount of space is available and a compact organization is required.

I claim as my invention:

1. A positive drive clutch for coupling and uncoupling two relatively rotatable members, comprising a driving element permanently connected to one of said members, a driven element posi-' tively connected to the other member, said elements being coaxial and movable axially relatively to one another and each having a multiplicity of face jaws projecting axially from its end face, said jaws being adapted to engage with and disengage from one another to couple and uncouple the clutch and provide a positive drive in either direction of rotation, the driving pressure faces of said jaws being substantially parallel with the axis of said elements and inclined relative tothe radii of said elements thereby to produce a tangential wedging action of said jaws upon rotating said elements to transmit pressure from one element to the other.

2. A positive drive clutch for coupling and uncoupling two relatively rotatable members, comprising a driving element permanently connected to one of said members, a driven element positively connected to the other member, said elements being coaxial and movable axially relatively to v I I one another and each having a multiplicity of face jaws projecting axially from its end face, said jaws being adapted to engage with one another and positively transmit pressure upon rotating said elements in either direction, the driving pressure faces of said jaws being substantially parallel with the axis of said elements and inclined at a constant angle to the radii of said elements thereby to produce a tangential wedging action between said jaws upon transmitting driving pressure from said driving element to said driven element and the opposite faces of said jaws being also inclined at a constant angle to the radii of said elements to produce a tangential wedging action between said jaws upon transmitting backlash pressures from said driven to said driving element.

3. A positive drive clutch for coupling and uncoupling two relatively rotatable members, comprising a driving element permanently connected to one of said members, a driven element positively connected to the other member, said elements being coaxial and movable axially relativelyto one another and each having a multiplicity of face jaws projecting axially from its end face, said jaws being adapted to engage with one another and positively transmit pressure upon rotating said elements in either direction, the driving pressure faces of said jaws being substantially parallel with the axis of said elements and inclined at a constant angle to the radii of said elements thereby to produce a tan: gential wedging action between said Jaws upon transmitting driving pressure from said drlvmg.

element to said driven element and the opposite faces of said jaws being also inclined at a. constant angle to the radii of said elements to produce a tangential wedging action between said jaws upon transmitting backlash pressures from said driven to said driving element and said last.

named faces being also rounded to permit ready engagement of said laws.

4. A positive drive clutch adapted to transmit power in either direction for coupling and uncoupling two relativelymovable members, comprising a driving element and a driven element, means connecting one of said elements with one of said members and positive means for coupling and uncoupling the other of said elements with the other movable member, said driving and driven elements havinga plurality of teeth extending radially therefrom and permanently in mesh with one another, the pressure faces of said teeth being inclined so as to produce a helical wedging action therebetween.

5. A positive drive clutch adapted transmit Y power in either direction for coupling and uncoupling two relatively movable members, comprising a driving element and a driven element, means connecting one of said elements with one of said members and positive means for coupling and uncoupling the other of said elements with the other movable member, said driving and driven elements each having a plurality of integral teeth extending radially therefrom and being permanently in mesh with the teeth of the other .element, the'pressure faces of said teeth being helically inclined so as to produce a helical wedging action therebetween and said wedging action moving one of said elements axially, and means yieldingly resisting the said axial movement of said element.

6. A positive drive clutch adapted to transmit power in either direction for coupling and uncoupling two relatively movable members, comprising a driving element and a driven element,

means connecting one of said elements with one of said members and positive means for coupling and uncoupling the other of saidelements with the other movable member, said driving and driven elements-each having a plurality of integral teeth extending radially therefrom and being permanently in mesh with the teeth of the other element, the pressure faces of said teeth being helically inclined so as to produce a helical wedg ing action therebetween, and said wedging action moving one of said elements axially, means yieldingly resisting the said axial movement of said element, and means forming a positive limit stop for said axial movement of said element.

'7. A positive drive clutch adapted to transmit power in either direction for coupling and uncoupling two relatively rotatable members, comprising a ringelement having a rowot integral radially extending teeth, an element having a row of integral radially extending teeth meshing permanently with the teeth of said ring element, means connecting one of'said elements with one of said members and positive jaw means for coupling and uncoupling the other of said elements with the other rotatable member, the faces of said teeth being helically inclined so as to produce a wedging action and cushion the strains in either direction of drive.

8. A positive drive clutch adapted to transmit power in either direction for coupling and uncoupling two relatively rotatable members, comprising a ring element having a plurality of integral, radially extending, helically inclined teeth, an element having a plurality of integrally, radially extending, helically inclined teeth permanently meshing with theteethof said-ring element, means connecting oneot said elements with one of said members, positive jaw means tor coupling and uncoupling'the other of said. elements with the other rotatable member, said teethproducing a helical wedging action and urging the corresponding parto! one said elements axially, and means yieldingly resisting said axial movement.

9. A positive drive clutch adapted to transmit power in either directionior coupling and uncoupling two relatively rotatable members, com-- prising a ring element having a row of integral, radially extending, helically inclined teeth, an element having a row of integral radially extending, helically inclined teeth permanently meshing with the teeth of said ring element, means connecting one of said elements. with one oisaid members, positive Jaw-means for coupling'and uncoupling the other of said elements with the other movable member whereby said teeth producea helical wedging action tending to drive one of said elements axially, andyielding means permitting a limited axial movement of said ring element.

10. A clutch for coupling and uncoupling two relatively rotatable members, comprising a ring element secured to one 0! said members and having inclined teeth, an axially movable elementhaving inclined teeth permanently meshing with said inclined teeth of said ring element whereby said teeth produce a wedging action driving said axially movable element axially, a flange carried by said first named rotatable member and limiting the axial movement of said axially movable between said first named rotatable member and element away therefrom, spring means interposed said axially movable element and holding said as to produce a wedging action therebetween upon moving said members in-the direction in which pressure is transmitted through said'iaws and the helical arrangement ot said teeth likewise producing a wedging action and means for yieldingly resisting the axial movement of said ring under the influence oi. said wedging action. I

1 FREDERICK E. MUNSOHAUEL annular row oihelical teeth permanently 

